Digital identifiers are central to information retrieval and management, so they are consequently crucial to the operation of the World Wide Web. In particular, the ability to identify a digital or real-world, physical resource and/or a description of such a resource relies on its unique identification.

What need is there for unique identifiers?

Put in relatively non-technical language, there is an increasing concern in information science in general to uniquely identify different things, organisations or people that could otherwise be confused, whether on the Internet or in the physical world. In technical terms, these are all referred to as resources (even if people might find it vaguely demeaning in normal language to be considered as such).